Effect of Electric Field Regulation on Laser Damage of Composite Low-Dispersion Mirrors

Yuhui Zhang,Yuxin Leng,Yanzhi Wang,Jianda Shao,Hongbo He,Ruiyi Chen,Ruxin Li,Zhihao Wang,Yuchuan Shao,Meiping Zhu,Yunxia Jin,Yuanan Zhao,Dawei Li,Kui Yi

doi:10.3390/coatings11010065

Yuhui Zhang, Yuxin Leng + Show 12 more

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https://doi.org/10.3390/coatings11010065

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Abstract

Low dispersion mirrors are important because of their potential use in petawatt (PW) laser systems. The following two methods are known to increase the laser-induced damage threshold of low dispersion optical components: use of a wide-bandgap-material protective layer and control of electric field distribution. By controlling the electric field distribution of composite low-dispersion mirrors (CLDM), we shift the electric field peaks from the material interface into the wide-bandgap material. However, the damage threshold of modified-electric-field composite low dispersion mirror (E-CLDM) does not increase. Damage morphology shows that the initial damaged layer is Ta2O5. An immediate cause is the enhancement of the electric field in internal layers caused by surface electric field regulation. Theoretical calculations show that the damage threshold of CLDM or E-CLDM is determined by the competition results of bandgap and the electric field of layer materials. The CLDM with different materials or different protective layer periods can be optimally designed according to the electric field competition effect in the future.

Highlights

The development of high-power petawatt (PW) laser promotes the development of physics, medicine, biology and materials science [1,2,3,4,5]
This is consistent with that expected for the E-composite low-dispersion mirrors (CLDM) stack, which performs to the CLDM stack
Both electric-field composite low dispersion mirror (E-CLDM) and CLDM stacks provide a reflectivity of 99.5% over a spectral range of 750–850 nm

Summary

Introduction

The development of high-power petawatt (PW) laser promotes the development of physics, medicine, biology and materials science [1,2,3,4,5]. The generation of high-power pulses is constrained by the laser-induced damage threshold (LIDT) of optical elements. The LIDT of a low-dispersion mirror (LDM) is a weak point in the development of high-power ultrafast systems [6]. LDMs that can afford a broadband high-reflection (HR) spectrum, high LIDT, and stable group delay dispersion (GDD) play an essential role for PW lasers with pulses in the femtosecond regime [7]. Reflection bandwidth, dispersion and damage threshold are interdependent, restricting each other [8]. Thereby, the LIDT of broad-bandwidth, low-dispersion mirrors have become a recognized research focus [8,9,10,11,12,13,14,15,16]

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